JP3843848B2 - Organic electroluminescence display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an organic EL display device that performs display using light emission of organic electroluminescence (hereinafter simply referred to as organic EL).
[0002]
[Prior art]
Conventionally, as an organic EL display device, for example, there is one disclosed in JP-A-11-8070.
[0003]
That is, as shown in FIG. 6, the organic EL layer 102 is disposed on the back surface (upper surface in the drawing) of the glass substrate 101. A transparent first electrode layer 103 is formed on the front surface (lower surface in the drawing) of the organic EL layer 102. A second electrode layer 104 is formed on the back surface of the organic EL layer 102. A color filter 106 is formed on the front side of the first electrode layer 103 so as to correspond to each light emitting portion 105 in which the first electrode layer 103 and the second electrode layer 104 overlap with each other through the organic EL layer 102. Has been.
[0004]
The color filter 106 is surrounded by a black mask 107 formed on the back surface of the glass substrate 101. The color filter 106 and the black mask 107 are covered with a transparent overcoat layer 108. Thus, by surrounding the color filter 106 with the black mask 107, it is possible to prevent light scattered in the color filter 106 from entering the adjacent pixel region.
[0005]
[Problems to be solved by the invention]
However, in the technique of the above publication, the height of the black mask 107 from the back surface of the glass substrate 101 is lower than that of the first electrode layer 103. Accordingly, there is a problem that light enters the adjacent pixel region through the overcoat layer 108 between the black mask 107 and the first electrode layer 103, causing light leakage and color blurring, resulting in unclear display. It was.
[0006]
An object of the present invention is to provide an organic EL display device capable of reliably suppressing the incidence of light to adjacent pixel regions.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the black mask is disposed so as to surround the front side (the emission direction side) of each light emitting portion. Accordingly, it is possible to suppress the incidence of light on adjacent pixel regions. And in this invention, the black mask is extended to the position more than the front surface of a 1st electrode layer in the side of this light emission part with respect to all the said light emission parts. Therefore, in the light emitting portion, at least the front side of the first electrode layer is surrounded by the black mask, and it is ensured that light is incident on the adjacent pixel region.
[0008]
According to a second aspect of the present invention, in the first aspect, the black mask extends to a position beyond the front surface of the organic EL layer on a side of the light emitting portion with respect to all of the plurality of light emitting portions. Therefore, in the light emitting portion, the side of the organic EL layer is surrounded by the black mask, and the light incidence to the adjacent pixel region is more reliably suppressed.
[0009]
According to a third aspect of the present invention, in the first or second aspect, a color filter is disposed in front of the light emitting portion, and the black mask is disposed so as to surround the color filter in front of the light emitting portion. ing. That is, in the structure in which the color filter is arranged in front of the light emitting unit, the light leakage path to the adjacent pixel region tends to be complicated. Applying the invention of claim 1 or 2 in such an aspect is particularly effective in achieving the effect (reliable suppression of the incidence of light on adjacent pixel regions).
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment embodying the organic EL display device of the present invention will be described in detail.
As shown in FIGS. 1 and 2, a black mask 12 is formed in a lattice pattern on the back surface 11 a of the glass substrate 11. The black mask 12 is made of, for example, resin black in which carbon, titanium, or the like is dispersed in a photoresist. The black mask 12 is formed using, for example, a photolithography technique. Note that the resin mask is easier to form the black mask 12 than, for example, metal chromium.
[0011]
Color filters 13R, 13G, and 13B are formed in the sections 12a of the black mask 12 on the back surface 11a of the glass substrate 11, respectively. That is, the black mask 12 is disposed so as to surround the color filters 13R, 13G, and 13B. As the color filters 13R, 13G, and 13B, organic color filters having better color reproducibility than inorganic color filters are used. The color filters 13R, 13G, and 13B are made of any of R (red), G (green), and B (blue), and the combination of these three colors shown in FIG. 1 is one pixel (pixel) of the organic EL display device. ). That is, each section 12a of the black mask 12 constitutes a subpixel region.
[0012]
An overcoat layer 14 is formed on the black mask 12 and the color filter 13 so as to cover them. The overcoat layer 14 is made of a transparent inorganic material (for example, silicon dioxide or silicon nitride). For example, a vapor deposition technique is used to form the overcoat layer 14. In the overcoat layer 14, accommodating recesses 15 are formed corresponding to the respective sections 12 a of the black mask 12.
[0013]
A transparent first electrode layer (anode) 16 is formed on the overcoat layer 14 by using, for example, a vapor deposition technique. The first electrode layer 16 is made of ITO (indium tin oxide) or the like, and is formed in a plurality of parallel stripes on the overcoat layer 14. Each stripe of the first electrode layer 16 is formed so as to pass through the accommodating recess 15 of the overcoat layer 14. Therefore, the first electrode layer 16 is laminated on the inner bottom surface 15 a of the accommodating recess 15. Yes.
[0014]
The organic EL layer 17 is composed of, for example, a known white light emitting layer. The organic EL layer 17 is formed in a plurality of parallel stripes extending in a direction orthogonal to the first electrode layer 16 while being separated by an insulating partition (not shown). Each stripe of the organic EL layer 17 is formed so as to pass through the accommodating recess 15 of the overcoat layer 14, and is laminated on the back surface (upper surface in the drawing) 16a of the first electrode layer 16 in the accommodating recess 15. ing.
[0015]
The second electrode layer (cathode) 18 is laminated on the back surface 17a of the organic EL layer 17 formed in a stripe shape, and is in a state orthogonal to the first electrode layer 16 in the housing recess 15 of the overcoat layer 14. Is formed. Therefore, the first electrode layer 16 and the second electrode layer 18 overlap with each other through the organic EL layer 17 in the housing recess 15 of the overcoat layer 14, thereby forming a light emitting unit 19 corresponding to each subpixel. ing.
[0016]
In each light emitting section 19, when a voltage is applied between the first electrode layer 16 and the second electrode layer 18, the organic EL layer 17 positioned between the electrode layers 16 and 18 emits white light. . The white light from the organic EL layer 17 passes through the first electrode layer 16 and the overcoat layer 14 and the color filters 13R, 13G, and 13B disposed on the front side, that is, on the light emission direction side, and passes through the glass substrate 11. It is emitted from. The white light passes through the color filters 13R, 13G, and 13B, and then becomes light of a color corresponding to any of R (red), G (green), and B (blue) of the color filters 13R, 13G, and 13B. A desired color is reproduced in the pixel by the combination of the light emission of the R (red), G (green), and B (blue) sub-pixels.
[0017]
Now, as shown in FIG. 3, the black mask 12 extends to a position above the front surface 16 b of the first electrode layer 16 on the side of each light emitting portion 19. That is, the black mask 12 has a height La, in other words, a distance La from the back surface 11a of the glass substrate 11 to the opening end surface 12b of each section 12a. It is configured to have a distance Lb or more to the front surface (lower surface in the drawing) 16b.
[0018]
In particular, in the present embodiment, the black mask 12 extends beyond the front surface 16b of the first electrode layer 16 and the side of the first electrode layer 16 and the front surface 17b of the organic EL layer 17 on the side of each light emitting unit 19. It extends to a position reaching the side of the EL layer 17. That is, in the black mask 12, the distance La from the back surface 11a of the glass substrate 11 to the opening end surface 12b exceeds the distance Lc from the back surface 11a of the glass substrate 11 to the front surface 17b of the organic EL layer 17 of each light emitting unit 19. It is configured.
[0019]
Therefore, in each subpixel, not only the color filters 13R, 13G, and 13B and the overcoat layer 14, but also the side of the first electrode layer 16 and the side of the organic EL layer 17 of the light emitting unit 19 are surrounded by the black mask 12. Will be. Therefore, it is possible to reliably suppress the light generated in the organic EL layer 17 of each light emitting unit 19 from entering the adjacent pixel region (including the adjacent subpixel region).
[0020]
In this embodiment having the above-described configuration, the following effects can be obtained.
(1) The black mask 12 extends to a position above the front surface 16 b of the first electrode layer 16 on the side of the light emitting unit 19. Therefore, it is possible to reliably suppress the light from entering the adjacent pixel region, and a clear display without light leakage or color blur is possible.
[0021]
In particular, in the present embodiment, as a preferable mode in which the above-described effect (reliable suppression of light incidence to an adjacent pixel region) can be more effectively achieved, the black mask 12 has an organic EL layer on the side of the light emitting unit 19. 17 is extended to a position beyond the front surface 17b. As a more preferred embodiment, the black mask 12 extends to a position above the front surface 17 b of the organic EL layer 17 on the side of the light emitting portion 19. As a more preferable aspect, the black mask 12 extends to a position beyond the front surface 17 b of the organic EL layer 17 on the side of the light emitting portion 19.
[0022]
(2) The color filters 13R, 13G, and 13B are disposed on the front side of the light emitting unit 19, and the black mask 12 is disposed on the front side of the light emitting unit 19 so as to surround the color filters 13R, 13G, and 13B. ing. That is, in the structure in which the color filters 13R, 13G, and 13B are arranged in front of the light emitting unit 19, the distance between the light emitting unit 19 and the glass substrate 11 becomes long, and the light leakage path to the adjacent pixel region is complicated. It tends to be a neighbor. Applying the present invention in such an embodiment is particularly effective in achieving the effect (reliable suppression of the incidence of light on adjacent pixel regions).
[0023]
(3) The overcoat layer 14 is interposed between the color filters 13R, 13G, and 13B and the first electrode layer 16. That is, in the structure in which the overcoat layer 14 is disposed on the front side of the light emitting portion 19, the distance between the light emitting portion 19 and the glass substrate 11 becomes long, and the light leakage path to the adjacent pixel region tends to be complicated. is there. Applying the present invention in such an embodiment is particularly effective in achieving the effect (reliable suppression of the incidence of light on adjacent pixel regions).
[0024]
The overcoat layer 14 blocks moisture from the color filters 13R, 13G, and 13B. Therefore, the organic EL layer 17 can be protected from this moisture. The overcoat layer 14 planarizes the surfaces of the color filters 13R, 13G, and 13B. Therefore, even if the organic EL layer 17 is thin, the risk of a short circuit between the electrode layers 16 and 18 formed with the organic EL layer 17 interposed therebetween is reduced, and the reliability of the organic EL display device is improved. Furthermore, the overcoat layer 14 also serves to protect the color filters 13R, 13G, and 13B from thermal and chemical influences in the process of forming the first electrode layer 16.
[0025]
For example, the following embodiments can be implemented without departing from the spirit of the present invention. For example, as shown in FIG. 4, the above embodiment is changed, and the overcoat layer 14 is made of an organic material. In this way, it is possible to form the overcoat layer 14 having a predetermined thickness in a short time as compared with the case of forming with an inorganic material.
[0026]
In particular, in the embodiment of FIG. 4, an adhesive layer 20 made of an inorganic material is formed between the overcoat layer 14 and the first electrode layer 16. Therefore, the adhesiveness between the first electrode layer 16 and the overcoat layer 14 is improved. The adhesive layer 20 also serves to block moisture from the overcoat layer 14 and protect the organic EL layer 17 from this moisture. In this embodiment, the housing recess 15 is formed in the adhesive layer 20.
[0027]
For example, as shown in FIG. 5, the overcoat layer 14 is deleted in the above embodiment, and the first electrode layer 16 is directly laminated on the color filters 13R, 13G, and 13B. In this way, an organic EL display device can be provided at a low cost.
[0028]
For example, as shown in FIG. 5, the embodiment is changed, and the black mask 12 is extended to the position of the back surface 17 a or more of the organic EL layer 17 on the side of each light emitting unit 19. That is, the distance La between the opening end surface 12b of the black mask 12 and the back surface 11a of the glass substrate 11 is the distance between the back surface 11a of the glass substrate 11 and the back surface 17a of the organic EL layer 17 in the light emitting unit 19. It is configured to be equal to or greater than Ld (La = Ld in the embodiment of FIG. 5). In this way, the sides of the organic EL layer 17 are all surrounded by the black mask 12 in each light emitting unit 19, and it is possible to further reliably prevent light from entering the adjacent pixel region.
[0029]
-The said embodiment is changed and the black mask 12 is formed, for example with metal chromium.
A technical idea that can be grasped from the above embodiment will be described.
[0030]
(1) The organic EL display device according to (1), wherein the black mask is extended to a position beyond a front surface of the first electrode layer on a side of the light emitting portion.
(2) The organic EL display device according to (1), wherein the black mask extends to a position above the front surface of the organic EL layer on a side of the light emitting portion.
[0031]
(3) The organic EL display device according to (2), wherein the black mask is extended to a position above the back surface of the organic EL layer on a side of the light emitting portion.
(4) The organic EL display device according to claim 3, wherein an overcoat layer for protecting the organic EL layer and / or the color filter is formed between the first electrode layer and the color filter.
[0032]
(5) The organic EL display device according to (4), wherein the overcoat layer is made of an inorganic material.
(6) The organic EL display device according to (5), wherein the overcoat layer is made of an organic material.
[0033]
(7) The organic EL display device according to (6), wherein an adhesive layer made of an inorganic material is formed between the overcoat layer and the first electrode layer.
[0034]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to reliably suppress the incidence of light to adjacent pixel regions.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an organic EL display device.
FIG. 2 is a schematic plan view illustrating a lattice shape of a black mask.
FIG. 3 is an enlarged view of a main part of FIG.
FIG. 4 is a schematic cross-sectional view of an organic EL display device showing another example.
FIG. 5 is a schematic cross-sectional view of an organic EL display device showing another example.
FIG. 6 is a schematic cross-sectional view of an organic EL display device showing a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 12 ... Black mask, 13R, G, B ... Color filter, 16 ... 1st electrode layer, 16b ... Front surface of 1st electrode layer, 17 ... Organic EL layer, 17a ... Back surface of organic EL layer, 17b ... Organic EL layer Front surface, 18 ... second electrode layer, 19 ... light emitting portion.

Claims (3)

An organic electroluminescence layer; a transparent first electrode layer formed on the front surface of the organic electroluminescence layer; a second electrode layer formed on the back surface of the organic electroluminescence layer; a first electrode layer and a second electrode layer; In an organic electroluminescence display device comprising a black mask arranged so as to surround each of the front sides of a plurality of light emitting portions that are overlapped with each other through an organic electroluminescence layer,
2. The organic electroluminescence display device according to claim 1, wherein the black mask is extended to a position equal to or higher than a front surface of the first electrode layer on a side of the light emitting portion with respect to all the light emitting portions. 2. The organic electroluminescence display device according to claim 1, wherein the black mask is extended to a position beyond a front surface of the organic electroluminescence layer on a side of the light emitting portion with respect to all of the plurality of light emitting portions.   3. The organic electroluminescence according to claim 1, wherein a color filter is disposed in front of the light emitting unit, and the black mask is disposed so as to surround the color filter in front of the light emitting unit. Display device.

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